1. Field of the Invention
This invention relates to traffic congestion monitoring systems and, more particularly, to such systems designed to warn drivers of approaching traffic congestion on roadways while driving.
2. Description of the Related Art
Many drivers listen to radio stations that broadcast current traffic condition information during commuter periods. When a traffic report is broadcast, the report includes locations of “slow downs” or accidents, hereinafter known as traffic affecting events, throughout the listening region of the radio station. Drivers are required to listen closely to the entire report to determine whether one of the traffic affecting events reported concerns his or her commute. One problem with radio traffic reports is that traffic affecting events in the entire region are given which may not affect a particular driver. Also, because the length of the report is limited to 15 to 30 seconds, the number of traffic affecting events reported is restricted or the report is spoken at a fast rate, making it incomprehensible to the driver. Lastly, drivers may not be that familiar with the areas or addresses given for the traffic affecting events given during the report and will not know whether it will affect their commute.
Many motor vehicle manufacturers offer Global Positioning System (GPS)-based navigational systems in their motor vehicles. Such systems are very popular because they give drivers visual and audible guidance over the routes they drive. Such systems include a GPS receiver that receives signals from twenty orbiting satellites operated by the U.S. Department of Defense and a map database that indicates the driver's current location on a map of the region. Using the map database, drivers are able to select various routes to a desired destination in the region. The map database is stored on optical discs (i.e. CD-ROM or DVD-ROM disc) that are played in a disc player connected to the GPS receiver and located inside the motor vehicle.
The map and route guidance features are particularly useful because they enable drivers to select different routes and to request instructions to a chosen destination. When activated and traveling, the map and route guidance features present a map of the region with the current location of the motor vehicle and the roadways along the selected route highlighted. As the motor vehicle travels on the route, the map is constantly updated so that the motor vehicle's current location is always presented, along with approaching and passing roadways and intersections. Although most GPS-based navigational systems prevent the driver from entering new destinations while moving, most allow the driver to manually request a detour or a new route to a given destination if the need arises.
Except for the satellites, the GPS-based navigation system is located entirely inside the motor vehicle. The visual display, which is connected to the GPS receiver, is typically mounted on the center console of the motor vehicle. In many motor vehicles, the visual display is a “touch screen” with a plurality of menu buttons that enable the driver to activate the system, select previously traveled destinations, request route guidance and enter alphanumeric characters to search for addresses, intersections, and the names of new destinations.
What is needed is an inexpensive traffic congestion avoidance system that can be easily coupled to a motor vehicle's GPS-based navigational system that informs a driver of traffic affecting events in his vicinity or that may affect the roadways on his route so that he may select a detour or other routes to avoid the traffic affecting event.